STUDY OF PATHOGENIC AMG3B2E FBOM BOMBAY. 
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colony, and which had not become encysted, to be dissolved, 
the amoebae appearing to break up, melt, and disappear. 
On one occasion this condition was brought about by stirring 
up and spreading a little of the yellow coccus colony which 
was growing in the midst of a luxuriant culture of amoebae. 
These observations lead me to believe that a very delicate 
balance is maintained in a successful culture of amoebae and 
bacteria. While on the one hand the amoebae eat up and 
digest the bacteria, the bacteria, on the other hand, seem to 
produce some substance or substances which at one time 
stimulates the amoebae to multiply, at another time actually 
brings about their destruction. 
From what has been said above it is evident that I have 
not succeeded in showing that this amoeba can absorb its 
food osmotically or live successfully without living bacteria; 
but I think certain lines for future research have been opened 
up which may ultimately explain the necessary connection 
which seems at present to exist between bacteria and the 
development and multiplication of amoebae outside the body. 
No one can be more conscious of the incompleteness of the 
work detailed above than myself. This paper has been 
written only because an opportunity may not present itself 
in the immediate future to continue this inquiry on my return 
to duty in India. It seems to me important, in the presence 
of a number of different species of amoeba)' which may be 
found inhabiting the human intestine or in dysenteric lesions, 
that greater care should be taken in distinguishing one 
species from another, and specially the pathogenic from 
harmless commensal amoebae. 
Conclusions. 
Two distinct species of amoeba) isolated from a liver- 
abscess have been cultivated on an agar medium. One at 
least of these amoebae in cultures does not multiply in the 
absence of living bacteria. The same bacteria which, when 
